Spark plug cleaner



O 1 19 3- F. L. DAVIS 2,332,063

SPARK PLUG CLEANER V Filed April 21, 1945 3 Sheets-Sheet l INVENTOR.fia/v/r Z fie ws Mmm.

Oct. 19, 1943. F. L. DAVIS SPARK PLUG CLEANER Filed April 21, 19 43 3Sheets-Sheet 2 INVENTOR. fim/wr Z. flaws BY ME 071% rrak/vsy 19, 1943.F. L. DAVIS 2,332,063

SPARK PLUG CLEANER Filed April 21, 1943 3 Sheets-Sheet 'INVEN TOR.

Patented Oct. 19, 1943 UNITED STATES PATENT OFFICE SPARK PLUG CLEANERFrank L. Davis, College Point, Long Island, N. Y. 7

Application April 21, 1943, Serial No. 483,971"

17 Claims.

The invention here disclosed relates to apparatus for cleaning sparkplugs and particularly the plugs used in aircraft engines.

The cleaning of plugs used in aircraft engines involves specialdifficulties. These plugs customarily have a center electrode and aseries of cooperating radial projections forming the second or outerelectrode. These projections close in the end of the spark plug to avery material extent, making it diflicult to reach in behind them forcleaning away accumulations of carbon and foreign matter between theouter shell and the insulating support for the center electrode.

The cleaning of these plugs is usually carried out as a part of theoverhaul routine of aircraft engines. It has been impossible to use theordinary mechanical spark plug cleaners around these overhaul jobsbecause of the dust and fine abrasive which these cleaners release intothe surrounding air. I

Special objects of the present invention are i to provide a spark plugcleaner capable'of reaching in behind the electrodes of the typicalaircraft engine plug and of thoroughly and efiiciently scouring andcleaning the same and which with all the necessary action required tosecure these results, will be perfectly safe to use right intheimmediate vicinity where the engines are being overhauled or othernecessarily fine work is being done.

Another special object is to guard against any possibility of accidentlyreleasing a blast of the cleaning medium into the air, as throughfailure to properly cover a spark plug inserted in the machine.

Other objects of the invention are to create a more elfective form ofcleaning blast, to automatieally screen the carbon out of the usedabrasive and in general to provide a machine having all the foregoingattributes, which will be of practical, rugged design and so simple instructure and number of parts that it may be produced at reasonablecost.

Other desirable objects will appear in the course of the followingspecification, in which the novel features of the invention aredescribed and broadly claimed.

The drawings accompanying and forming part of the specificationillustrate certain of the present practical commercial embodiments ofthe invention. Structure however, may be modified and changed as regardsthe present disclosure, all within the true intent and broad scope ofthe invention as hereinafter defined and claimed...

Fig. l in the drawings is a broken vertical sectional View of one of themachines as in actual use.

Fig. 2 is an enlarged broken sectional detail substantially on line 22of Fig. 1, illustrating the automatic switch control.

Fig. 3 is a horizontal part sectional view of the machine as on line 33of Fig. 1 but on a smaller scale.

Fig. 4 is an enlarged'broken sectional view of the rotary plug holderand blast nozzle structure.

Fig. 5 is a cross-sectional view of the blast nozzle as on line 5-5 ofFig. 4.

Fig. 6 is a broken sectional detail of the nozzle control valve as online 5-5 of Fig. 4.

Fig. 7 is a broken sectional view illustrating a modified form of theinvention.

Fig. 8 is an enlarged broken sectional detail of an adjustable form ofblast nozzle.

Fig. 9 is a face view of a special wrench and gage for accuratelyadjusting the blast nozzle.

Fig. 10 is a diagrammatic View illustrating the provision of a pluralityofdifferently positioned or angled scouring nozzles.

In Fig. 1, an aircraft typeplugis indicated at 7, held seated in thecentral opening 8, in an adapter 9, by an overstanding arm Ill,projecting from a sleeve ll, tensioned downwardly .on post l3, by aspring l2.

Adapters such as 9, may be provided for different sizes and styles ofplugs, each arranged to support the plug or plugs for which itis'intended with the open end of the plug exposed to the blast from thecleaning nozzle,

These adapters may be of rubber or like elastic material, to grip andhold the plug and to hold in place removably seated in an open socket M,in the rotary support or pulley l5. l

The latter is shown in detail in Fig. 4, as having an internal annulusit, which may be an oilless bushing, journalled on an upstanding annularbearing flange l1, and riding on a step or thrust bearing l8. The lattermay be the depressed inner annular flan of a collar [9,

confining a ring of packing material 23, against" cured on the top plate2!, of the cabinet structure,.about the central opening 22.

The annular member l4, forming the adapter socket is shown as removablysecured to the surrounding pulley structure by screws 23, and thissocket member is shown as having an annular outstanding cupped flange24, welded or otherwise secured thereto andconfining a gasket or ring ofpacking material 25, against the underside of the top plate 2!.

Also dependent from the rotary socket portion of the pulley is afrusto-conical form of shield 25. A lining 21, of rubber or likematerial is shown extending up over the inner face of this shield andthrough the central opening 28, in such shield outwardly over the rim ofsuch opening at 29, to form a gasket, sealing against the lower end ofthe shell of the plug.

The rotary plug holder described is driven in the present instance, by asmall motor 38, and suitable reduction gearing, including small pulley3|, and belt 32, passing around the pulley flange [5, at slow speed,such as less than 1 R. P. M.

A pointer 33, is shown projecting out from the pulley flange to registerwith suitable index markings such as 34, Fig. 3, to enable one to easilymake sure that the holder has completed at least one full revolution.

The blast nozzle is shown in Fig. 4, as made up of two companion shellmembers 35, 35, screwed together to form a mixing chamber 31, having anabrasive opening 38, in the base of the same and a central dischargenozzle in the opposite end.

The discharge nozzle is shown as made up of a rubber sleeve 39,constricted in its central par tion to engage and be held in the opening40, in the end of the chamber and flared out at the inner end at 4!, tofit the inner surface of the chamber and flared to a less extent to itsouter end to form a cupped discharge orifice 42.

Extending axially into the back end of the mixing chamber is an air pipe43, constricted to a nozzle 44, spaced in back of and dischargingthrough the orifice piece 42.

Within the air conduit there is shown a heli cally twisted deflector 45,for imparting rotation to the issuing air flow.

Similarly within the surrounding chamber there is provided a vane orseries of vanes 26, for imparting twist to the cloud of abrasiveentering this chamber through conduit 47. The latter conduit as shown inFig. 1, dips into the body of abrasive contained in the holder 48, andmay have one or more branches, as indicated at E9, to reach all portionsof this container.

The rotation imparted to the abrasive entering the chamber 31-, createsa dispersion and forms. more or less of a cloud of these grains whichwith their dispersion and rotative movement are picked up the morereadily and forcibly carried forward by the rotating blast of airissuing from the air nozzle 44.

The abrasive nozzle is supported with its discharge end a short distancebelow the shell of the supported plug and inclined to direct the blastwithin the. conical shield and upwardly at an angle against the innerwall of the plug sheh.

The spacing of the nozzle a short distance below the end of the plug andthe inclination of the jet from one side across to the far side of theplug shell fans out the jet sufficiently to project the scouring blastfully around all sides of the radial projections 58, of the outerelectrode. H

The nozzle is shown supported in the inclined relation described byextending the air pipe 43, through an inclined shelf or bracket 51projecting inwardly from the wall of the enclosure .52, and byengagement of the nuts 53, on the threaded exterior of said pipe atopposite sides of said bracket or shelf. 7

Compressed air is supplied in the present disclosure by a pump 54,operated by motor 55, and connected by piping 56, with a valve body 51,Fig. 6, ported to carry air through piping 58, to the nozzle pipe 43, orto carry air through piping 58, into the upper end of the chamber 37,beyond and above the central injector nozzle 44. A ported valve plug 60,rotatable in said valve body by external handle 6|, provides a controlfor directing either a scouring blast or an abrasive-free cleaning blastfrom the nozzle.

To effect a separation of the carbon and dirt removed from the plugs,from the abrasive, there is provided in the illustration, an inclinedscreen 62, over the abrasive compartment 48, of a mesh to generallyexclude the flaky carbon particles and to pass the grains of abrasive.The greasy character of the carbon is an assisting factor, enabling thecarbon to slide more freely over the inclined screen while the abrasivedrops through.

The screening action described is aided and promoted in the presentdisclosure by mounting the motor and pump within and supported by thecabinet structure 63, and by employing a ieciprocating type of pump,such as a diaphragm pump which at the high speed it is normally run,will create a definite vibration, imparting to the screen a desirablecontinuous shaking movement. Thus this separator has the full efiiciencyof a shaking screen, without taking oii any useful energy forvibratingthe screen.

The carbon and accompanying dirt is delivered off the lower end of theinclined shaking screen into a pocket or well 54, from which it may beremoved at 65.

The nozzle supporting shelf 5|, is shown as placed directly above thedirt trap 64, and as inclined inwardly and downwardly toward the upperend of the screen, thus to act as a baille, which will deflect materialaway from such trap and force it to traverse the separating screen.

At the opposite side of the cleaning chamber 52, from the batlle 5!,there is shown an inwardly inclined baffle 66, extending upwardly fromthe upper end of the screen, in back of the conical shield and louveredat 61, for passage of air into an air escape conduit 68 which extendsdownwardly below a, body of kerosene or other dust trapping and sealingliquid in the bottom of an air exhaust chamber 68. This chamber maycontain a layer or layers of glass wool or other dust packing l0, andmay have one or more vents or openings H, in the upper portion forrelease of the purified air.

To avoid any possibility of escape of abrasive or dust laden air at thetop about the rotating spark plug holder, there is provided in theillustration a transparent hood l2, hingedly mounted on the cabinet at13, to cover the rotary holder, the plug holddown l0 and the belt driveconnections to the holder.

Use is also made of this hood to insure that the power willnot be thrownon to set the machine in operation until the parts are properlyprotected. In the illustration, the hood carries a downwardly extendingcam projection 14, at one side which will project through a narrow slot15, in the cabinet top to throw on the control switch 16, when the hoodis fully closed and conversely to let this switch open as soon as thehood is released or starts to open. This switch may control both thepump motor and the plug holder rotating motor. If desired, the plugholder may be driven through reduction gearing directly from the pumpmotor.

The concealment of the, switch within the cabinet and the operation ofthe same from a cam carried by the hood and projecting through a smallopening in the cabinet provides a desirable simple safety interlock forpreventing operation until the machine is fully closed but other or ad.-ditional safety. features may be provided.

The rubber adapters are desirable because they yieldingly holdthemselves seated in the rotary carrier and yieldingly hold the sparkplugs in properly sealed relation in such carrier. The spring holddownassures the plug remaining sealed in its seated position during theentire cleaning operation. lhe rubber lining to the conical shield,engaged by the shell of the plug assists in this complete sealing of theplug inthe operative position. They spring holddown is easily lifted andswung out of the way in the removing and placing of plugs in themachine.

Usually only one complete rotation of the plug is necessary for athorough scouring action.- The pointer 33 provides an easy guide forthis operation. In practice, the holder may be slipped around one way orthe other, using the pointer as a handle and the machine started withthe pointer at the near index mark, that is, the mark 34, to the left inFig. 3 and the machine continued in operation until the pointer passesthis mark and goes beyond that to the next mark, thus making sure of afull complete rotation,

After making one turn with the abrasive on,

that is, with the control valve as in Fig. 6, the valve handle 6|, maybe turned to bypass the air through the upper line 59, to flush out anyloose particles in the scoured plug with clean air.

The rotation of both the air from the injection nozzle and the abrasiveentering the nozzle chamber assures a concentrated uniform jet ofabrasive and the direction of this concentrated blast on an inclineinwardly across the transverse axis of the plug assures a thoroughscouring of the plug interior behind the radially pro- J'ecting portionsof the outer electrode.

In the machine illustrated, the motor driven pump imparts vibration tothe rotating spark plug holder as well as to the carbon separatingscreen. This is advantageous in actually shaking free carbon particlesloosened in the plug in the scouring action of the blast from thenozzle.

The protective hood may be sealed by a gasket such as indicated. at H,and this may be sufficiently elastic to allow enough movement of thehood to actuate'the control switch while the hood remains closed. Thusin the illustration, the hood is sealed by this gasket as soon as it islowered, but slight additional pressure is required to close the switch.This is a further safety feature, for if at any time this closingpressure is released, this resilient gasket will raise the hood withoutactually opening it, enough to throw the switch off.

The air filter is shown supported in spaced relation below the top ofthe cabinet, so as to provide ample space for release of the air throughthe screen "H, in the top of this filter. The sides of the cabinetmay bescreened as indicated at it, for free flow of air into and out of thesame.

To promote desired vibration, the cabinet may be mounted on resilientsupports, such as indicated at T9.

A gage 89, is shown in Fig. 3, hooked in on the pressure line from thepump so that the operator may check the action when the machine isclosed and in operation.

, A small door 81, is'shown in the top of the cabinet directly above theair filter, providing convenientaccess forsupplying this filter with thesealing and purifying liquid.

In the modified form of:the invention illustrated in Fig. '7, an airblast cleaning nozzle is indicated at 82, separate, and apart from theabrasive nozzle 35, and the latter is shown supported so that it may beadjusted both as to angle of inclination and spacing from the plugin theholder.

For purposes of such adjustments, the nozzle is shown pivotallysupported at 83, substantially on the longitudinal axis of the plug by aspring arm 84, and the inclined shelf or baiile 5|, as shown aspivotally mounted at 85, and as having an adjustable connection with thenozzle.

In the illustration, the nozzle pipe t3, has a sliding mounting at 86,in a slotted portion 81, of said shelf. A hand screw 88, projectingthrough a spherical nut 89, sealed in a universal clampmounting 99, inthe side of the casing, has a universal ball joint connection M, withthe pipe fitting 92, so that turning of this screw will rock the nozzleon pivotal axis 83, thus to adjust the angle of inclination of thescouring blast.

A similar hand screw 93, projecting through a sealed ball bearing nut94, and having a universal connection 95, with the shelf, provides meansfor raising and lowering said shelf and hence raising and lowering thenozzle, the spring pivot arm 84, yielding suificiently for suchadjustments. i

By adjusting eitheror both screws 88, 93, the nozzle may be set to bestadvantage to clean different kindsand sizes of spark plugs.

Fig. 7 also illustrates how the rotary plug holder made be made up froman annular ball bearing unit, preferably of the sealed type, by securingthe inner race-ring 96, fast to the supporting structure and securingthepulley flange i5, and the socket 14, fast to the outer race ring 91.

To compensate for wear, the nozzle may be constructed as shownparticularly in Fig. 8, by providing a gland 98, about the neck of'theorifice lining, having a beveled inner end 99, bearing on the inclinedexternal shoulder Hill of the lining, so that with taking up on thegland screws IUI, the throat of the lining will be contracted asindicated in the dotted lines at I02.

A special wrench, such as shown at H23 in Fig. 9 may be provided foradjusting these screws and this wrench may have a stem portion 134 of asize to form a gage for the proper size of the throat orifice.

To'facilitate desired adjustments of the nozzle, the-adjusting screws 88and 93, Fig. 7, may have suitable scales I95, I06, associated with them.These scales may show the inclination and positioning of the nozzle inrespect to the plug.

According to one method of operation, the nozzle is at one inclination,such as indicated in Fig. '7, for one revolution of the plug and theninclined at a different angle for one or more additional revolutions ofthe plug, assuring the blast reaching all internal walls of the plugs.

In the form of the invention illustrated in Fig. 10, two blast nozzles35, 35a, are provided, inclined at different angles, possibly spaceddifferent distances from the end of the plug and disposed to jet theabrasive at different sections of the plug, so as to reach all surfaces,and without one stream interfering with the other stream of abrasive.With such a constructionas this, all

portions of the plug to be scoured will be reached in a singlerevolution of the plug.

What is claimed is:

1. A spark plug cleaner, comprising a rotatably mounted spark plugholder having a central opening to receive and expose the end portion ofa spark plug, means for positively rotating said holder, a nozzlepositioned to direct a blast of cleaning medium toward the edge portionof said spark plug opening at an angle to the axis of a plug seated insaid opening, means for supplying a blast of cleaning medium to saidnozzle and for at the same time initiating operation of said means forrotating said spark plug holder, a deflecting shield about the open endof said rotating holder, a carbon separating screen in the line ofmaterial deflected by said shield and an abrasive collector behind saidscreen.

2. A spark plug cleaner, comprising a rotatably mounted spark plugholder having a central opening to receive and expose the end portion ofa spark plug, means for positively rotating said holder, a nozzlepositioned to direct a blast of cleaning medium toward the edge portionof said spark plug opening at an angle to the axisof a plug seated insaid opening, means for supplying a blast of cleaning medium to saidnozzle and for at the same time initiating operation of said means forrotating said spark plug holder, a blast confining shield carried bysaid rotating spark plug holder, an air escape chamber about saidrotating shield, a liquid seal dust removing air filter and a conduitextending from said air chamber into the liquid seal of said air filter.

3. A spark plug cleaner, comprising a park plug holder, a nozzlecooperatively related: to said spark plug holder and having a mixingchamber, compressed air and abrasive conduits extending to said mixingchamber and means associated with the respective conduits for-impartingrotative movement to both the compressed air and the abrasive meeting inthe mixing chamber of said nozzle.

4. In a spark plug cleaner,,a blast nozzle having a chamber terminatingin a constricted outlet, said chamber having an abrasive inlet, andprovided with a. vane or vanes for imparting whirling motion to,abrasive entering saida chamher and passing to said outlet and acompressed air conduit enteringsaid chamber and discharging through saidoutlet, said conduit having a vane or vanes for imparting whirlingmotion to compressed air flowing. therethrough and discharging into saidoutlet.

5. A spark plug cleaner, comprising a cabinet, an abrasive container insaid cabinet, an inclined carbon separating screen for said containerand of a mesh to pass carbon-freed abrasive, an abrasive dischargingnozzle in the cabinet above said screen, a spark plug holder mounted inthe cabinot above said nozzle, an abrasive conduit extending from saidabrasive container to said nozzle, a compressed air conduit extending tosaid nozzle and a motor driven air compressor carried by said cabinet,said compressor being of the reciprocating type and attached to saidcabinet to impart vibration, thereto and to the spark plug holder andinclined screen mounted in said cabinet.

6. A spark plug cleaner, comprising a cabinet, an abrasive container insaid cabinet, an inclined carbon separating screen for said containerand of a mesh to pass carbon-freed abrasive, an abrasive dischargingnozzle in the cabinet above said screen, a spark plug holder mounted inthe cabinet above said nozzle, an abrasive conduit extending from saidabrasive container to said nozzle, a compressed air conduit extending tosaid nozzle and a motor driven air compressor carried by said cabinet,said compressor being of the reciprocating type and attached to saidcabinet to impart vibration thereto 'and to the spark plug holder andinclined screen mounted in said cabinet, said nozzle being mounted insaid cabinet toward the lower end of the inclined screen and inclined insubstantially the same direction as said screen and a baflle at the backof said nozzle inclined downwardly toward the lower end of said inclinedscreen.

7. A spark plug cleaner, comprising a cabinet, an abrasive container insaid cabinet, an inclined carbon separating screen for said containerand of a mesh to pass carbon-freed abrasive, an abrasive dischargingnozzle in the cabinet above said screen, a spark plug holder mounted inthe cabinet above said nozzle, an abrasive conduit extending from saidabrasive container to said nozzle, a compressed air conduit extending tosaid nozzle and a motor driven air compressor carried by said cabinet,said compressor being of the reciprocating type and attached to saidcabinet to impart vibration thereto and to the spark plug holder andinclined screen mounted in said cabinet, said nozzle being mounted insaid cabinet toward the lower end of the inclined screen and inclined insubstantially the same direction as said screen, a bafllle at the backof said nozzle inclined downwardly toward the lower end of said inclinedscreen and a carbon collecting chamber in the cabinet below the lowerend of the screen and beneath said inclined bafile.

8. A spark plug cleaner, comprising a spark plug holder, means fordirecting a jet of scouring fluid into a spark plug supported in saidholder and including a motor driven pump, a controller for said motordriven pump, a movable cover over said spark plug holder, means on saidmovable cover for effecting operation of said controller, a cabinetwithin which said controller is located,

' said cabinet having a small opening in line with said controller andsaid means including a small projection on said cover operable throughsaid small opening into operative relation to said controller.

9. A spark plug cleaner, comprising an abrasive nozzle having a chamberhaving an abrasive opening in one end, a discharge outlet at theopposite end and an air inlet near said opposite end, an injector nozzleentered in said chamber and directed into said discharge passage, andair supply piping to said air inlet and to said injector nozzleincluding a two-position valve operative to direct fluid either to saidair inlet or to said injector nozzle.

10. In a spark plug cleaner, a blast nozzle comprising a chamber havinga discharge outlet in one end and a resilient liner in the form of asleeve having a restricted central portion engaged in said outlet andcupped portions at opposite ends of the same, one within and the otherwithout said chamber.

11. In a spark plug cleaner, a rotary spark plug holder, a nozzle fordirecting a cleaning blast at a spark plug seated in said holder, drivemeans for rotating said holder and means for indicating completerevolutions of said rotary holder, including a projecting pointercarried by said holder and a relatively stationary marker cooperablewith said pointer, said holder being freeto be turned by said pointerfor the purpose of arbitrarily positioning the same in respect to saidmarker.

12. A spark plug cleaner, comprising a cabinet, a rotary spark plugholder journalled in the top of said cabinet, anupstanding post on thetop of said cabinet at one side of said rotary holder, a spring pressedsleeve slidingly guided on said post and having a laterally projectingarm engageable over the end of a spark plug seated in said rotary holderand means within said cabinet for directing a blast of cleaning fluid ata spark plug seated in said rotating plug holder, a blast nozzle forcleaning a plugseated in said holder, means for pivotally supportingsaid nozzle, means for angularly adjusting said nozzle on its pivotalsupport, means for bodily shifting said pivotally mounted nozzle to:-ward and away from said spark plug holder, an

enclosure about said nozzle, said adjusting means projecting to theoutside of said enclosure and indicating means associated with theexposed portions of said adjusting means.

15. A spark plug cleanen comprising a spark plug holder, a blast nozzleassociatedtherewith, said nozzle having a discharge outlet,a'compressible liner seated in said discharge outlet and "means on saidnozzle for variably contracting the throat portion of said liner.

16. A spark plug cleaner,comprising a spark plug holder, a nozzlepositioned to direct a stream of abrasive toward a spark plug positionedin said holder, a support for said spark plug holder and abrasivenozzle, said support being mounted for vibratory movement, a motordriven air compressor connected with said nozzle and mounted on saidsupport to impart vibratory movement thereto and a screen positioned forscreening the abrasive discharged by during operation of said motor'drivenair compressor."

17. A spark plug cleaner, comprising a cabinet having a top "with anopening therein, a spark plug holder rotatably mounted in line with saidopening, said rotatable holder having a spark plug seat in the top ofthe same and having a blast confining shield at the bottom of the sameand within the cabinet, a dust excluding packing between said shield andthe top' structure of the cabinet, motor operated belt drive connections above the cabinet top for rotating said spark plug holder and aspark plug cleaning nozzle below the cabinet top and directed into theshield carried by said rotating spark plug holder.

FRANK L. DAVIS.

